The sleep study allows extensive monitoring of your bodies' activities while you sleep and allows a sleep specialist to determine whether any abnormalities are present in your sleeping pattern, muscle activity or breathing during the night. In some instances a sleep lab may have the ability to test people in their own homes or in other areas of the hospital with portable monitoring equipment.
Some of the activities of the body monitored during a sleep study usually include the following:
- Brain activity (electroencephalogram, EEG)
- Muscle activity (electromyogram, EMG)
- Heart activity (electrocardiogram, ECG)
- Eye activity (electrooculogram, EOG)
- Chest and stomach movements
- Airflow at nose and/or mouth
- Body oxygen level (light transmission through finger/ear-lobe)
- Sleeping position
If the sleep technician easily confirms that you have sleep apnea in the early part of the night you may have what is called a ‘split-night study' (half diagnosis, half titration). After about four hours of observing how you sleep the technician will wake you to initiate CPAP. While on CPAP the technician will continue to monitor you and measure the effectiveness of this treatment. This process can be done over two full nights in some cases.